Construction Of New Chiral Organic Catalysts Containing Ferrocene Blocks And Their Catalytic Asymmetric Addition And Oxidation Reactions

Chiral chemicals have been widely used as catalysts, reagents and intermediates in the fields of chemistry, medicine, pesticides, hormones and food additives. It is of great importance for scientists to prepare chiral compounds because many of them have very important biological activities. The main strategies for asymmetric synthesis of pure chiral compounds are:(1) Asymmetric synthesis by using chiral compounds as starting material; (2) Asymmetric synthesis via asymmetric induction; (3) Asymmetric synthesis via catalytic asymmetric reactions. Arguably, the ideal strategy is the asymmetric synthesis via organocatalytic asymmetric reactions. Ferrocene-based compounds have been broadly used in the fields of material science and industrial catalysis due to their ideal properties such as low price, thermal stability, high rigidity, low toxicity, controllable steric hindrance and ease of derivatization.In this thesis, a series of ferrocene-based bifunctional amine-thioureas and a new generation of ferrocene-based chiral hypervalent iodine organocatalysts have been designed and synthesized on the basis of recent advance of thiourea catalysts and hypervalent iodine catalysts. And the catalytic activities and stereoselectivities of those new catalysts have been explored by the application of them to asymmetric reactions. The follo wings is the summary of the research results:1 Three types of eleven ferrocene-based bifunctional amine-thiourea catalysts (Ⅰ, Ⅱ, Ⅲ) have been synthesized in 4 steps via azidation and catalytic hydrogenation using (R)-Ugi’s amine as starting material. The asymmetric Michael addition of acetylacetone to nitroolefins catalyzed by these novel bifunctional catalysts afford the Michael adducts in up to 98% yield and up to 96% excellent enantioselectivities. Among of these catalysts, (Rc,SFc,Sc)-5j is the best one which provides the adduct in almost quantitative yield with 96% ee.2 Three new ferrocene-based chiral hypervalent iodine catalysts A, B, C were synthesized using (R)-Ugi’s amine, ferrocene and ferrocenecarboxylic acid as starting material, respectively. The asymmetric dearomatizing spirolactonization of naphthols catalyzed by the newly-synthesized catalysts in the presence of m-CPBA afforded the spirolactones in low 10% yield with 20% enantioselectivities. Further work in our lab is ongoing to improve the catalytic activity and stereoselectivity.